19-5985; Rev 0; 7/11
MAX98307 Evaluation Kit
Evaluates: MAX98307
General Description
The MAX98307 evaluation kit (EV kit) is a fully assembled
and tested circuit board that evaluates the MAX98307
filterless Class DG multilevel amplifier to drive a speaker
in portable audio applications. The EV kit comes with a
MAX98307 IC in a 16-pin TQFN-EP package. Designed
to operate from a 2.6V to 5.25V DC power supply, the EV
kit is capable of delivering 3.3W into an 8I load. The EV
kit accepts a differential or a single-ended input signal.
Features
S Filterless
Operation Passes Radiated Emissions
with Up to 30cm of Speaker Cable
S 2.6V
to 5.25V Single-Supply Operation
S Delivers
Up to 3.3W Into an 8I Speaker
S Configurable
Gain Control
S Differential
or Single-Ended Input
S Low-Power
Shutdown Input
S Proven
PCB Layout
S Fully
Assembled and Tested
Ordering Information
appears at end of data sheet.
Component List
DESIGNATION
QTY
DESCRIPTION
0.1FF
Q10%,
16V X7R ceramic
capacitors (0603)
Murata GRM188R71C104K
0.33FF
Q10%,
16V X7R ceramic
capacitors (0603)
Murata GRM188R71C334K
4.7FF
Q10%,
16V X7R ceramic
capacitor (0805)
Murata GRM21BR71C475K
10FF
Q20%,
6.3V X5R ceramic
capacitor (0603)
Murata GRM188R60J106M
10kI
Q1%
resistors (0603)
20kI
Q1%
resistors (0603)
Class DG audio amplifier
(16-TQFN-EP)
Maxim MAX98307ETE+
OUT-
OUT+
R5, R6
R7, R8
SU1, SU2
TP0
—
1
1
0
2
2
0
1
DESIGNATION
C9–C13
C14–C17
FOUT-, FOUT+,
PGND, PVDD
IN
JU1
JU2
QTY
0
0
4
1
1
1
DESCRIPTION
Not installed, capacitors (0603)
Recommended:
Murata GRM188R71C224K
Not installed, capacitors (0603)
Binding posts
Red, right-angle, PC-mount
RCA jack
3-pin header
2-pin header
Not installed, inductors—short
(PC trace)
Recommended:
Sumida CDRH65-220M
Black test point, 63 mil drill size
Red test point, 63 mil drill size
Not installed, resistors (0603)
Recommended:
22I
Q5%
resistors (0603)
0I
Q5%
resistors (0603)
Shunts (JU1, JU2)
Not installed, test point
(15 mil drill size)
PCB: MAX98307 EVALUATION
KIT
MINIMAL COMPONENTS FOR CUSTOMER DESIGN
C1, C2, C3
3
C4, C5
2
C6
1
C7
R1, R2
R3, R4
U1
1
2
2
1
L1, L2
0
OPTIONAL COMPONENTS FOR CUSTOMER
EVALUATION
C1N, PVSS
C1P
C8
2
1
1
White test points, 40 mil drill size
Red test point, 40 mil drill size
10FF
Q20%,
6.3V X5R ceramic
capacitor (0603)
Murata GRM188R60J106M
_________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX98307 Evaluation Kit
Evaluates: MAX98307
Component Suppliers
SUPPLIER
Murata Electronics North America, Inc.
Sumida Corp.
PHONE
770-436-1300
847-545-6700
www.sumida.com
WEBSITE
www.murata-northamerica.com
Note:
Indicate that you are using the MAX98307 when contacting these component suppliers.
Quick Start
• MAX98307 EV kit
Recommended Equipment
The EV kit is shipped with a gain of +14.5dB. Change the
resistors (R1–R4) to customize the gain of the EV kit. Refer
to the MAX98307/MAX98308 IC data sheet for details.
The EV kit is shipped with filterless outputs by default.
The EV kit’s filterless outputs, available at the OUT+,
OUT- test points or the FOUT+, FOUT- binding posts,
can be connected directly to a speaker load without any
filtering. Use the OUT+, OUT- test points or the FOUT+,
FOUT- binding posts to connect a speaker directly to the
device’s outputs.
Audio analyzers typically cannot accept pulse-width-
modulated (PWM) signals at their inputs. Therefore, the
EV kit provides component footprints for a lowpass filter
at its outputs to ease evaluation. Cut open the PCB traces
between inductor L1 and L2 pads. Install inductors L1,
L2, capacitors C9–C13, and resistors R5, R6 (provided
with the EV kit) and use the filtering output binding posts
(FOUT- and FOUT+) to connect the filtered PWM outputs
to the audio analyzer. The default lowpass filter at the EV
kit outputs is optimized for an 8I speaker.
The IC can pass CE EN55022B regulations with up to
30cm of speaker cable and no filtering. However, ferrite-
bead filters can be used to achieve further attenuation
of radiated emissions. To install the ferrite-bead filters,
verify that filter inductors L1 and L2 are not installed.
Next, replace shorting resistors R7 and R8 with 0603 or
smaller ferrite beads and install filter capacitors on the
C14 and C15 pads. The speaker wire should be con-
nected to the OUT- and OUT+ test points.
Customizing the Gain
• 2.6V to 5.25V, 2A power supply
• Audio source (e.g., CD player, MP3 player, etc.)
• 8I speaker
The EV kit is fully assembled and tested. Follow the steps
listed below to verify board operation.
Caution: Do not
turn on the power supply until all connections are
completed.
1) Install a shunt on pins 1-2 on jumper JU1 (EV kit on).
2) Verify that a shunt is not installed on jumper JU2
(differential input mode)
3) Connect the 8I speaker across the FOUT- and
FOUT+ PCB pads.
4) Connect the positive terminal of the power supply to
the PVDD PCB pad and the ground terminal to the
PGND PCB pad.
5) Connect the audio source output to the IN RCA jack.
6) Connect the ground terminal of the audio source to
the PGND PCB pad.
7) Turn on the audio source.
8) Turn on the power supply.
Filterless Output
Procedure
Filtered Output
Detailed Description of Hardware
The MAX98307 EV kit features the MAX98307 filterless
Class DG amplifier IC, designed to drive an 8I speaker
in portable audio applications. The EV kit comes with
a MAX98307 IC in a 16-pin TQFN package with an
exposed pad. The EV kit operates from a DC power sup-
ply that provides 2.6V to 5.25V and 2A of current. The EV
kit accepts differential or single-ended audio input and
provides a fully differential output. The audio input source
is amplified to drive up to 3.3W into an 8I speaker. The
device outputs, available at the OUT+, OUT- test points
or FOUT+, FOUT- binding posts, can be connected
directly to a speaker load without any filtering and up
to 30cm of cable. However, filter components can be
added to ease evaluation. See the
Filtered Output
sec-
tion for additional information.
Jumper Selection
Shutdown Mode (SHDN)
Jumper JU1 controls the shutdown pin (SHDN) of the IC.
The shutdown pin can also be controlled by an external
logic controller connected to the EV kit
SHDN
PCB pad.
Remove the shunt from JU1 before connecting an external
controller to the
SHDN
pad. See Table 1 for shunt positions.
Input Mode (IN-)
Jumper JU2 provides an option to select between a
differential or single-ended input mode for the EV kit. See
Table 2 for jumper JU2 configuration.
_________________________________________________________________
Maxim Integrated Products
2
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